scholarly journals Evaluation of the Genetic Variation of Cowpea Landraces (Vigna unguiculata) from Western Cameroon Using Qualitative Traits

2017 ◽  
Vol 9 (4) ◽  
pp. 508-514 ◽  
Author(s):  
Toscani NGOMPE-DEFFO ◽  
Eric Bertrand KOUAM ◽  
Honoré BEYEGUE-DJONKO ◽  
Mariette ANOUMAA

Characterization of the genetic diversity and analysis of the genetic relationship between accessions of a crop species is a key step in breeding superior cultivars. The main objective of the hereby study was to determine the genetic variation between 30 cowpea accessions collected throughout the eight divisions of the Western Region of Cameroon using qualitative traits. Phenotypic variation of these accessions was evaluated using diversity indices and cluster analyses. A total of twenty qualitative traits were used for the study. Fifteen of them (75%) were polymorphic, displaying each at least two phenotypic classes. The monomorphic characters were growth pattern, leaf color, leaf hairiness, plant hairiness and pod hairiness, each with only one phenotypic class. Results showed a relatively significant level of genetic diversity among the studied cowpea accessions. Overall, the average of the observed and effective number of phenotypic classes per qualitative trait were Na = 2.350 and Ne = 1.828 respectively. The Nei’s genetic diversity and the Shannon weaver diversity index were He = 0.369, ranging from zero (monomorphic trait) to 0.655 (growth habit) and H’ = 0.609, ranging from zero (monomorphic trait) to 0.996 (seed crowding), respectively. The dendrogram constructed from the twenty qualitative traits revealed 05 accessions clusters with the number of accessions in each cluster varying from one to eleven. Information obtained from this study is likely be useful for future cowpea breeding program.

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 487
Author(s):  
Trinity P. Hamm ◽  
Marcin Nowicki ◽  
Sarah L. Boggess ◽  
William E. Klingeman ◽  
Denita Hadziabdic ◽  
...  

The Viburnum genus is of particular interest to horticulturalists, phylogeneticists, and biogeographers. Despite its popularity, there are few existing molecular markers to investigate genetic diversity in this large genus, which includes over 160 species. There are also few polymorphic molecular tools that can delineate closely related species within the genus. Viburnum farreri, a member of the Solenotinus subclade and one of the centers of diversity for Viburnum, was selected for DNA sequencing and development of genomic simple sequence repeats (gSSRs). In this study, 15 polymorphic gSSRs were developed and characterized for a collection of 19 V. farreri samples. Number of alleles per locus ranged from two- to- eight and nine loci had four or more alleles. Observed heterozygosity ranged from 0 to 0.84 and expected heterozygosity ranged from 0.10 to 0.80 for the 15 loci. Shannon diversity index values across these loci ranged from 0.21 to 1.62. The markers developed in this study add to the existing molecular toolkit for the genus and will be used in future studies investigating cross-transferability, genetic variation, and species and cultivar delimitation in the Viburnum genus and closely allied genera in the Adoxaceae and Caprifoliaceae.


2013 ◽  
Vol 5 (1) ◽  
pp. 114-119 ◽  
Author(s):  
Özlem ÖZBEK ◽  
Betül Uçar GIDIK

In cultivated commercial crop species, genetic diversity tends to decrease because of the extensive breeding processes. Therefore, germplasm of commercial crop species, such as Brassica napus L. should be evaluated and the genotypes, which have higher genetic diversity index, should be addressed as potential parental cross materials in breeding programs. In this study, the genetic diversity was analysed by using randomly amplified polymorphic DNA analysis (RAPD) technique in nine Turkish commercial rapeseed varieties. The RAPD primers (10-mer oligonucleotides) produced 51 scorable loci, 31 loci of which were polymorphic (60.78%) and 20 loci (39.22%) were monomorphic The RAPD bands were scored as binary matrix data and were analysed using POPGENE version 1.32. At locus level, the values of genetic diversity within population (Hs) and total (HT) were 0.15 and 0.19 respectively. The genetic differentiation (GST) and the gene flow (Nm) values between the populations were 0.20 and 2.05 respectively. The mean number of alleles (na), the mean number of effective alleles (nae), and the mean value of genetic diversity (He) were 2.00, 1.26, and 0.19 respectively. According to Pearson’s correlation, multiple regression and principal component analyses, eco-geographical conditions in combination had significant effect on genetic indices of commercial B. napus L. varieties were discussed.


Parasitology ◽  
2002 ◽  
Vol 125 (7) ◽  
pp. S51-S59 ◽  
Author(s):  
J. CURTIS ◽  
R. E. SORENSEN ◽  
D. J. MINCHELLA

Blood flukes in the genus Schistosoma are important human parasites in tropical regions. A substantial amount of genetic diversity has been described in populations of these parasites using molecular markers. We first consider the extent of genetic variation found in Schistosoma mansoni and some factors that may be contributing to this variation. Recently, though, attempts have been made to analyze not only the genetic diversity but how that diversity is partitioned within natural populations of schistosomes. Studies with non-allelic molecular markers (e.g. RAPDs and mtVNTRs) have indicated that schistosome populations exhibit varying levels of gene flow among component subpopulations. The recent characterization of microsatellite markers for S. mansoni provided an opportunity to study schistosome population structure within a population of schistosomes from a single Brazilian village using allelic markers. Whereas the detection of population structure depends strongly on the type of analysis with a mitochondrial marker, analyses with a set of seven microsatellite loci consistently revealed moderate genetic differentiation when village boroughs were used to define parasite subpopulations and greater subdivision when human hosts defined subpopulations. Finally, we discuss the implications that such strong population structure might have on schistosome epidemiology.


Weed Science ◽  
2008 ◽  
Vol 56 (3) ◽  
pp. 394-399 ◽  
Author(s):  
Sarah M. Ward ◽  
Scott D. Reid ◽  
Judy Harrington ◽  
Jason Sutton ◽  
K George Beck

Intraspecific genetic variation may contribute significantly to invasiveness and control problems, but has been characterized to date in relatively few invasive weed species. We examined 56 intersimple sequence repeat (ISSR) loci in 220 individuals from 11 invading populations of yellow toadflax sampled across five western states. All populations showed high levels of genetic diversity. Estimated values for Shannon's diversity measure ranged from 0.217 to 0.388, and for expected heterozygosity from 0.178 to 0.260. Nei's total gene diversity index (HT), on the basis of all individuals across all populations, was 0.267. Partitioning of genetic variance using analysis of molecular variance revealed 1.7% of genetic variation among regional population groups, 29.1% among populations within groups, and 69.2% within populations, consistent with expectations for an outcrossing species but suggesting little geographic differentiation. Pairs of adjacent individuals identical at all ISSR loci that appeared to be ramets of a single clone were detected in only one population. This indicates that patch expansion in yellow toadflax is driven more by sexual reproduction via seed than by rhizomatous clonal spread, at least at the spatial scale of sampling for this study. Eight populations had significant values for Mantel's R at P = 0.05, suggesting some fine-scale positive genetic structuring, possibly from restricted gene flow. Population clustering on the basis of Nei's genetic distance between populations and unweighted pair group method with arithmetic mean did not reflect geographic location. It is likely that multiple introductions of this species have occurred across the Intermountain West, followed by extensive genetic recombination. High levels of genetic diversity within yellow toadflax populations pose management challenges, as already seen in reports of variable response to herbicide application and limited impacts of biocontrol agent releases.


Author(s):  
DJOUHER GAAD, MERIEM LAOUAR ◽  
FATIMA GABOUN ◽  
AISSA ABDELGUERFI

In the present study an attempt has been made to characterize lentil accessions based on qualitative traits. There were variations among 44 lentil accessions. Erect growth habit was observed in 24 % of the accessions where 8% were from Algeria. Conversely, prostrate growth habit was observed in 34% of the accessions. The majority of the remaining accessions (41.32%) were intermediate. Stem with anthocyanin pigmentation was showed in 44% of the accessions, whereas, 56% had no pigmentation (green stem). About half of the accessions had grey green leaves (53%) and 23% of accessions were light green. Among the characters, flower color showed the highest variation. White flowers were observed in 64% accessions and violet flowers were found in 36% accessions. Flowers, with violet stripes in the standard petal (SVE) were observed in 44% accessions and the majority (56%) lacked violet stripes. Yellow cotyledons were observed in 61% accessions, while the rest (39%) had red cotyledons. The majority of accessions (81%) were observed with brown testa while 14% were green and 5% had yellow testa. Absence of seed coat pattern was observed in 69% accessions. However, 8% accessions with spots, 5% with dots, 16% were marbled and the remaining 2% were complex. Flattened seed shape was observed in 60% of accessions. Conversely, globose shape was observed in 40% of the accessions, among of them 27% were from Algeria.


2017 ◽  
Vol 47 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Magdalena Szeliga ◽  
Joanna Ciura ◽  
Mirosław Tyrka

Abstract Chemical and genetic characterization of Veratrum species deposited in European collections is important for genepool preservation and identification of populations with desired metabolic properties. Veratrum album, V. lobelianum and V. nigrum are native to Europe, and in Poland are ranked as rare or threatened. Genetic variation of European Veratrum species was characterized by Amplified Fragment Length Polymorphism (AFLP) markers. The accumulation of jervine as a representative of steroidal alkaloids was measured in seeds. Distribution of 380 markers generated from eight primer combinations was useful for studying genetic relationships among and within species in the Veratrum genus and the most divergent populations were identified. Genetic variation between 12 populations of Veratrum species supports the classification of V. lobelianum as a subspecies of V. album. However, the results need further validation on extended material. A higher genetic diversity (22.3%) was observed between populations of V. nigrum as compared to V. album (14.5%). Contents of jervine allowed for discrimination of the studied Veratrum species and can be used as a potential chemotaxonomic marker. The highest jervine levels were found in V. album. V. nigrum seeds had only trace amounts and no jervine was detected in seeds of V. lobelianum.


2019 ◽  
Vol 11 (4) ◽  
pp. 417-420
Author(s):  
James T. OPOOLA ◽  
Matthew OZIEGBE

Ocimum tenuiflorum Linn. (Lamiaceae) is an aromatic plant with a lot of potential medicinally, industrially and domestically. There are different morpho-types of O. tenuiflorum, with different shades of purple pigment on their leaves. Very few studies have been done to study the genetic variation among O. tenuiflorum morpho-types. Thus, in the present study, four O. tenuiflorum morpho-types that varied in pigmentation were characterised using RAPD marker as a molecular tool. Eight different primers collectively amplified 64 bands in the four morpho-types analysed. The RAPD technique revealed that the varied amount of purple pigment in O. tenuiflorum morpho-types is not due to environmental factor alone. The UPGMA clustering algorithm based on RAPD data grouped the four morpho-types into two major groups, with O. tenuiflorum (T2) with very light purple leaves and stem morpho-type, more related to O. tenuiflorum (T3) that have deep purple leaves and stem. The result was able to show the phylogenetic relationships within the species. The low level of genetic diversity observed in O. tenuiflorum can be attributed to the mode of reproduction and the reproductive biology of the species, due to the fact that they are likely to be natural hybrids produced through cross pollination.


2019 ◽  
Vol 99 (4) ◽  
pp. 833-839
Author(s):  
Son Quang Do ◽  
Lan Thi Phuong Nguyen ◽  
Thinh Hoang Nguyen ◽  
Trung Quoc Nguyen

In this study, partial mitochondrial DNA (mtDNA) D-loop sequences of three Vietnamese indigenous chicken varieties, including Mong Tien Phong, To, and Sau Ngon, were analyzed to access genetic diversity and the maternal lineages of origin. A 525 bp fragment of the mtDNA D-loop region was sequenced from a total of 61 chickens of the three varieties. A neighbor-joining phylogenetic tree was assembled from the haplotypes obtained and reference sequences of mtDNA D-loop sequences of Red Junglefowl and domestic chickens from National Center for Biotechnology Information database. Genetic diversity indices and analysis of molecular variance were performed. Evaluation of genetic relationships between the three varieties was carried out with pairwise fixation index (FST). In total, 16 haplotypes were identified in the chickens studied. These haplotypes were classified in three haplogroups (A, B, and E) with the majority grouped in haplogroup B and haplogroup E. All three chicken varieties studied were distributed into 2–3 haplogroups and all three haplogroups found in this study are also represented by Red Junglefowl. In conclusion, all three Vietnamese indigenous chicken varieties have likely originated from multiple maternal lineages and potentially descended from the Red Junglefowl.


2017 ◽  
Vol 9 (10) ◽  
pp. 76 ◽  
Author(s):  
Paola F. Fazzi-Gomes ◽  
Nuno F. Melo ◽  
Glauber Palheta ◽  
Jonas Aguiar ◽  
Iracilda Sampaio ◽  
...  

The present study analyzed the genetic variability and structure of farmed tambaqui in the Brazilian state of Pará, and provided basic information that can be used for the development of programs of monitoring and management of genetic resources in the aquaculture operations of northern Brazil. A total of 216 individuals were sampled from tambaqui farms in Pará. Genotyping was based on a multiplex set of 10 tri- and tetra-nucleotide microsatellite markers. The data were used to calculate genetic diversity indices, expected and observed heterozygosity, the number of alleles per locus, allelic richness, and inbreeding coefficient. Genetic structure was verified using DEST and RST, the genetic signature, and Bayesian analysis. The results showed that the tambaqui farms surveyed have suffered a significant loss of genetic variability, and that they are genetically structured, forming two clusters, one encompassing the farms in western Pará, and the other including the farms from the northeast and southeast regions of the state. These finding provide fundamental insights for the development of effective strategies that will help guarantee productivity and the quality of the tambaqui farms of northern Brazil, and provide a database for the upgrading of the genetic variability of these populations. This study indicated the need for hatcheries in southeastern and northeastern Pará to amplify or renew their breeding stocks, in order to avoid the significant loss of genetic diversity in the tambaqui farms of these regions.


2008 ◽  
Vol 43 (No. 3) ◽  
pp. 97-104 ◽  
Author(s):  
L. Leišová ◽  
L. Kučera ◽  
L. Dotlačil

Barley (<i>Hordeum vulgare</i> L.) and oat (<i>Avena sativa</i> L.) are important crop species. 1865 accessions of winter barley, 2707 accessions of spring barley and 1998 accessions of oat are maintained in RICP Gene bank. The expert core collection is used to be established as a tool for germplasm study, conservation of genetic variability and for the identification of useful genes. The main aim of this study was to evaluate genetic diversity of barley and oat genotypes within the expert core collections. Genetic variation of 176 barley accessions was analyzed using 26 microsatellite loci, covering all 6 chromosomes. 330 oat accessions were analyzed using 26 microsatellite loci that are mapped only into linkage groups. For 26 barley microsatellite loci, 328 alleles were detected. The average number of alleles per locus was 12.6. In oat, for 26 oat microsatellite loci, 353 alleles were detected. The average number of alleles per locus was 13.6. The average DI (diversity index) was 0.11 in barley and 0.09 in oat. Dendrogram and PCA (Principal Component Analysis) based on microsatellite data showed a different influence of the place of origin, age of variety and pedigree on grouping into clusters. PCA showed that the breeding process had a negative impact on the level of genetic diversity and therefore there is a necessity of barley and oat germplasm conservation.


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